Focal seizures Flashcards
what is the definition of focal seizures?
Focal seizures (formerly known as partial seizures) refer to the electrical and clinical manifestations of seizures that arise from one portion of the brain.
what is the epidemiology of focal siezures?
Most common type of seizure in adults
Higher in people under 20
Higher in men
what is the aetiology of focal seizures?
Traumatic brain injury CNS infection Brain tumours MCDs IC vascular malformations Stroke Alzheimer’s Perinatal injury Family history / genetics
what are the risk factors for focal seizures?
Febrile seizure Traumatic brian injury CNA infetin Stroke Brain Tumour Learning difficulty Dementia Family history Intracranial vascular malformations MCDs Male
what is the pathophysiology of focal seizures?
Neurochemical and neurophysiological features thought to be relevant to the development of focal seizures include: Neurotransmitter disturbances (e.g., an imbalance between inhibitory gamma-aminobutyric acid [GABA]-ergic and excitatory glutaminergic neurotransmitters) Alterations in neuronal and glial cell structures, such as voltage-gated sodium channels, voltage-gated calcium channels, gap junctions (connexins), SV2A synaptic protein vesicles, G-protein-coupled receptors, A or M voltage-gated potassium channels, and ionotropic glutamate receptors.
what are the key presentations of focal seizures?
Presence of risk factors
Movement of one side of body or one part
Premonitory sensation or experience (fear epigastric sensation, deja vu)
Automatisms (smacking lips)
Temporary aphasia (language and speech)
Staring or being unaware of surroundings
what are the signs of focal seizures?
risk factors
what are the symptoms of focal seizures?
Movement of one side of body or one part
Premonitory sensation or experience (fear epigastric sensation, deja vu)
Automatisms (smacking lips)
Temporary aphasia (language and speech)
Staring or being unaware of surroundings
what are the first line and gold standard investigations for focal seizures?
Blood glucose - extreme hypoglycaemia or hyperglycaemia can cause provoked focal seizures
FBC - elevated WBC count can indicate a central nervous system infection
Electrolyte panel - electrolytes disturbances
Toxicology screen - illicit substance use
Lumbar puncture and CSF - if CNS infection is suspected
CT head - intracranial haemorrhage, skull fracture, presence of structural lesion
MRI brain - anatomical temporal lobe abnormalities (mesial temporal sclerosis, neoplastic lesions, vascular malformations, and developmental lesions)
EEG - focal spikes or sharp waves with associated slowing of the electrical activity in the area of the spikes
what are the differential diagnoses for focal seizures?
Syncope TIA Sleep disorders Tic disorders Chores Tremor
how are focal seizures managed?
Acute repetitive:
Benzodiazepine
Ongoing:
Anticonvulsant (lamotrigine, levetiracetam), other first line, dual therapy, neurostimulation, diet changes
how are focal seizures monitored?
Patients taking anticonvulsant drugs for focal seizures should be followed up on a regular basis. The frequency of follow-up depends on several factors. Patients whose seizures are well controlled and who are not having adverse effects with medication may be seen every 6 months to 1 year. Patients having their medications adjusted or titrated should be seen every 1 to 2 months until they are stable. Intervening telephone or video follow-up may substitute for interval visits.
what are the complications of focal seizures?
Head trauma None fracture Memory loss Mood disorders SUDEP
what is the prognosis of focal seizures?
Nearly two-thirds of patients with focal seizures achieve adequate seizure control with anticonvulsant drugs, either monotherapy or polytherapy. There is no evidence to guide the timing of medication withdrawal in seizure-free adults, but most patients are treated with anticonvulsants for at least 2 years
